syzbot

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BUG: KMSAN: uninit-value in addr_bit_set net/ipv6/ip6_fib.c:146 [inline]
BUG: KMSAN: uninit-value in fib6_lookup_1+0x1f1/0x9e0 net/ipv6/ip6_fib.c:1337
CPU: 1 PID: 9117 Comm: syz-executor6 Not tainted 4.17.0+ #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1368
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:634
 addr_bit_set net/ipv6/ip6_fib.c:146 [inline]
 fib6_lookup_1+0x1f1/0x9e0 net/ipv6/ip6_fib.c:1337
 fib6_lookup+0x188/0x2d0 net/ipv6/ip6_fib.c:1407
 ip6_pol_route+0x373/0x5d40 net/ipv6/route.c:1698
 ip6_pol_route_output+0x11b/0x140 net/ipv6/route.c:1969
 fib6_rule_lookup+0x323/0x7a0 net/ipv6/fib6_rules.c:85
 ip6_route_output_flags+0x504/0x5a0 net/ipv6/route.c:1997
 ip6_dst_lookup_tail+0x2fc/0x1a50 net/ipv6/ip6_output.c:995
 ip6_dst_lookup_flow+0xfc/0x270 net/ipv6/ip6_output.c:1096
 inet6_csk_route_req+0x451/0x630 net/ipv6/inet6_connection_sock.c:55
 tcp_v6_syn_recv_sock+0x905/0x30e0 net/ipv6/tcp_ipv6.c:1133
 tcp_check_req+0x1bb6/0x1ff0 net/ipv4/tcp_minisocks.c:782
 tcp_v6_rcv+0x2810/0x6660 net/ipv6/tcp_ipv6.c:1489
 ip6_input_finish+0x1353/0x2260 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x498/0x6e0 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x1d6b/0x2360 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47f3/0x4aa0 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
 napi_poll net/core/dev.c:5735 [inline]
 net_rx_action+0x766/0x1a80 net/core/dev.c:5801
 __do_softirq+0x592/0x979 kernel/softirq.c:285
 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
 </IRQ>
 do_softirq kernel/softirq.c:329 [inline]
 __local_bh_enable_ip+0x114/0x140 kernel/softirq.c:182
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:728 [inline]
 ip6_finish_output2+0x1ce8/0x2100 net/ipv6/ip6_output.c:121
 ip6_finish_output+0xaf0/0xbb0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:277 [inline]
 ip6_output+0x597/0x6c0 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_xmit+0x2067/0x2370 net/ipv6/ip6_output.c:277
 inet6_csk_xmit+0x35b/0x440 net/ipv6/inet6_connection_sock.c:139
 tcp_transmit_skb+0x3db5/0x5350 net/ipv4/tcp_output.c:1176
 tcp_write_xmit+0x2d81/0xb200 net/ipv4/tcp_output.c:2373
 tcp_push_one+0x195/0x230 net/ipv4/tcp_output.c:2560
 tcp_sendmsg_locked+0x400e/0x6610 net/ipv4/tcp.c:1390
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 inet_sendmsg+0x3fc/0x760 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 __sys_sendto+0x6c4/0x7e0 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0x1a1/0x210 net/socket.c:1797
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x455ab9
RSP: 002b:00007f61faef7c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f61faef86d4 RCX: 0000000000455ab9
RDX: fffffffffffffedd RSI: 0000000020000280 RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000020000080 R09: 000000000000001c
R10: 000000002000012c R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c10ba R14: 00000000004d1208 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:287 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:302 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:692
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:478
 fib6_lookup+0x225/0x2d0 net/ipv6/ip6_fib.c:1392
 ip6_pol_route+0x373/0x5d40 net/ipv6/route.c:1698
 ip6_pol_route_output+0x11b/0x140 net/ipv6/route.c:1969
 fib6_rule_lookup+0x323/0x7a0 net/ipv6/fib6_rules.c:85
 ip6_route_output_flags+0x504/0x5a0 net/ipv6/route.c:1997
 ip6_dst_lookup_tail+0x2fc/0x1a50 net/ipv6/ip6_output.c:995
 ip6_dst_lookup_flow+0xfc/0x270 net/ipv6/ip6_output.c:1096
 inet6_csk_route_req+0x451/0x630 net/ipv6/inet6_connection_sock.c:55
 tcp_v6_syn_recv_sock+0x905/0x30e0 net/ipv6/tcp_ipv6.c:1133
 tcp_check_req+0x1bb6/0x1ff0 net/ipv4/tcp_minisocks.c:782
 tcp_v6_rcv+0x2810/0x6660 net/ipv6/tcp_ipv6.c:1489
 ip6_input_finish+0x1353/0x2260 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0x294/0x320 net/ipv6/ip6_input.c:327
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x498/0x6e0 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x1d6b/0x2360 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47f3/0x4aa0 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
 napi_poll net/core/dev.c:5735 [inline]
 net_rx_action+0x766/0x1a80 net/core/dev.c:5801
 __do_softirq+0x592/0x979 kernel/softirq.c:285

Local variable description: ----skb.addr@__netif_receive_skb_core
Variable was created at:
 __netif_receive_skb_core+0xb7/0x4aa0 net/core/dev.c:4462
 __netif_receive_skb net/core/dev.c:4657 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5337
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